This invention relates to the sealing of expansion and contraction joints in buildings and pavements by installing elongated hollow resilient sealing members in such joints and more particularly to a novel method of installing such sealing members and the novel structural features required in such sealing members for installation by the novel method.
In the construction of buildings, highways, and the like in which concrete panels, slabs or sections are used, provision must be made for the expansion and contraction of the panels, slabs or sections due to changes in temperature, moisture content, etc. Thus, an appropriate spacing is provided between such panels, slabs or sections and adjacent structural elements, including other panels, slabs or sections. The channels or grooves formed by such spacing are conventionally sealed against entry of fluids and solids therein.
Initially, attempts were made to provide a satisfactory seal by forcing solid elastic material into the channel or groove. However, the range of expansion or contraction that can be accommodated without destroying the integrity of the seal was found to be small in view of the limited elastic characteristics of materials capable of providing a reasonable useful life when exposed to the harsh environment to which the exterior surfaces of buildings and pavements are subjected.
An early attempt to increase the range of expansion and contraction that could be accommodated was to preform the elastic material into an elongated sheet which was then forced into the channel or groove by folding the sheet along its axis of elongation. Thus, the resilience of the preformed sheet as a body, in addition to the elastic characteristics of the material, tended to increase the range of expansion and contraction that could be accommodated.
However, the contact area which provides the seal between the folded sheet and the sides of the channel tended to decrease rapidly when the channel widened. Thus, it has been proposed to preform the sealing member as an elongated resilient body of hollow cross-section and preferably of elastic material. An elongated body of hollow cross-section can be shaped to provide essentially constant contact area with the sides of the channel throughout the range of expansion and contraction to be accommodated thereby.
However, the installation of preformed elongated members of hollow cross-section has presented a problem in that such hollow cross-section must be collapsed to enable them to be installed in the channel. Although a folded sheet may be forced into the channel by placing it over the channel and applying pressure to a limited area thereof over the channel, the installation of a hollow body is more complicated. The application of pressure to the opposite side of a hollow body from the channel will simply cause the body to deform and bind against the sides of the channel. Thus, it has been proposed to collapse the hollow body by various means to enable it to be installed in the channel. For example, special tools for squeezing the hollow body transversely of the channel, or special means for evacuating the interior of the hollow body have been proposed. It has also been proposed to design the hollow body in such a way as to allow it to be pulled rather than pushed into the channel by appropriate tools received in the channel.
However, all of the methods and means for installing hollow bodies have required expensive, complicated and inconvenient tools and methods including specially shaped or dimensioned channels. Since thousands of feet of elongated hollow sealing members may be required on a given structure and, in the case of a building, such sealing members must be installed in locations which may be inconvenient and often at some height above the ground, it is necessary that a simple and convenient method be provided which does not require expensive and complicated tools or specially formed channels.
It is an object of this invention to provide an improved method of installing elongated hollow resilient sealing members in the expansion and contraction joints of buildings and pavements.
It is known in the prior art to provide elongated sealing members of both the folded type and the hollow type with various forms of projections or fingers on the exterior thereof adapted to engage the sides of the expansion and contraction joint in order to improve the seal therebetween. It is also known in the prior art to provide the interior of hollow resilient sealing members with various arrangements of struts and ribs adapted to maintain the compressive force exerted by the sealing member on the sides of the joint. However, bodies having external projections or internal ribs and struts are difficult to preform due to the difficulty of curing the elastic material which forms the projections, ribs and struts.
Another object of this invention is to provide improved elongated hollow resilient members which are not only suitable for installation by the improved method but which can be more easily and inexpensively preformed and cured than was possible according to the teaching of the prior art.